Sumner’s work has been shown in the Ann Arbor Film Festival, the San Francisco Art Institute Film Festival, the San Francisco Cinematheque, the Polyphonix International Festival, a Smithsonian Institution Traveling Exhibition, and the World Print Competition.

He has designed books for the Guggenheim Museum, the San Francisco Museum of Modern Art, Thames & Hudson, and Chronicle Books.

In 1979 he co-founded Burning Books with writer Melody Sumner Carnahan in Oakland, California, which has published thirty-three books.

In 1989 Sumner and Carnahan moved Burning Books to New Mexico where they continue to produce art and publish books.